The invention relates to a piston compressor having at least one cylinder and a piston guided therein in contact-free manner, which connected via a piston rod to a crosshead.
In piston compressors of this type the connection of the piston rod to the crosshead consists either of two nuts screwed to the piston rod, which can be screwed in relation to one another and between them clamp a wall part of the crosshead body which has correspondingly thick dimensions. Another possibility for the connection consists in the provision of a slot at right angles through the piston rod end and the crosshead body receiving said end, into which slot two wedges mutually abutting with their wedge faces can be inserted. Both embodiments have the disadvantage that with regard to the type of connection the crosshead body has to be constructed so that it is longer than would be necessary with regard to the length of its bearing surface in the cross head bearing. The distance between crosshead journal and the piston centre is consequently relatively large. This in turn necessitates the overall length of the compressor being great and the piston, which is guided in contact-free manner, having a tendency to perform relatively large radial movements.
In order to rectify this situation, in addition a piston rod guide bearing was previously installed between the crosshead bearing and the cylinder, which necessitates a large length of the piston rod and thus also of the compressor.